1. Field of the Invention
The present invention relates to a rotary hermetic compressor that configures a refrigeration cycle of, for example, an air conditioner, and to a refrigeration cycle system configuring a refrigeration cycle by using the rotary hermetic compressor.
2. Description of the Related Art
Generally or commonly used rotary hermetic compressors have a configuration of an intra-casing high pressure type that accommodates in a hermetic casing an electric motor section and a compression mechanism section coupled with an electric motor section, in which a gas compressed in the compression mechanism section is once discharged into the hermetic casing.
In the compression mechanism section, an eccentric roller is accommodated in a cylinder chamber provided in a cylinder, a vane chamber is provided in the cylinder, and the vane is accommodated therein. A front end edge is compressed and urged by a compression spring to normally extend to the side of the cylinder chamber so as to elastically contact a peripheral surface of the eccentric roller. The cylinder chamber is separated by the vane into two chambers along the rotation direction of the eccentric roller, in which a suction section is communicated to one of the chambers, and a discharge section is communicated to the other chamber. A suction pipe is connected to the suction section, and the discharge section is opened in the hermetic casing.
In recent years, two-cylinder rotary hermetic compressors having two cylinders of the type described above are being standardized. In a compressor of the type, if a cylinder for normally performing compression operation and a cylinder enabling compression-stopping switching can be provided, the specification is enhanced, and the compressor is thereby made advantageous.
For example, Jpn. Pat. Appln. KOKAI Publication No. 1-247786 (hereinafter, referred to as “Patent Document 1”) discloses a technique characterized by including two cylinder chambers and high-pressure introducing means that forcibly causes a vane of either one of the cylinder chambers to be away from a roller and that causes the cylinder chamber to be a highly pressurized to stop the compression operation.
In addition, Japanese Patent No. 2803456 (“Patent Document 2”, hereafter) discloses a technique in which a bypass pathway is provided as high-pressure introducing means for introducing high pressure from a hermetic container into a suction pipe. In one cylinder chamber, a vane is brought by operation of an elastic material into contact with a roller even during operation with an inoperative cylinder, and a compression chamber is normally separated by the vane.
A compressor disclosed in Patent Document 1 is functionally excellent. However, for configuring the high-pressure introducing means, a high-pressure introducing opening for communication between one of the cylinders and the hermetic casing is provided; a double-throttling mechanism is provided in a refrigeration cycle; and a bypass refrigerant pipe including a solenoid on-off valve is provided, the bypass refrigerant pipe being branched from a middle portion of the throttling mechanism for communication to one of vane chambers.
More specifically, for example, opening-forming processing is necessary, a throttle device on the refrigeration cycle has to be configured into the double-throttling mechanism, and further, the bypass refrigerant pipe has to be connected between the double-throttling mechanism and the cylinder chamber, so that the configuration is complicated to the extent of providing adverse effects.
In the previous technique disclosed in Patent Document 2, a connection step for the bypass pipe that bypasses a discharge side and a suction side to the hermetic container is necessary, thereby providing adverse effects in cost. In addition, the vane is normally brought into elastic contact with the roller even during the operation with an inoperative cylinder, such that the efficiency is reduced because of the presence of, for example, a slight amount of compression operation and a sliding loss.
The present invention is made under these circumstances, and an object thereof is to provide a rotary hermetic compressor in which, in a prerequisite condition in which first and second cylinders are provided, a compression urging structure for a vane of one of the cylinders is omitted to attain improvement in lubricity and reliability, and the number of components and the processing time and costs are reduced to thereby contribute to cost reduction; and a refrigeration cycle system using the rotary hermetic compressor.